TY  - JOUR
A1  - Franchini, Paolo
A1  - Jones, Julia C.
A1  - Xiong, Peiwen
A1  - Kneitz, Susanne
A1  - Gompert, Zachariah
A1  - Warren, Wesley C.
A1  - Walter, Ronald B.
A1  - Meyer, Axel
A1  - Schartl, Manfred
T1  - Long-term experimental hybridisation results in the evolution of a new sex chromosome in swordtail fish
JF  - Nature Communications
N2  - The remarkable diversity of sex determination mechanisms known in fish may be fuelled by exceptionally high rates of sex chromosome turnovers or transitions. However, the evolutionary causes and genomic mechanisms underlying this variation and instability are yet to be understood. Here we report on an over 30-year evolutionary experiment in which we tested the genomic consequences of hybridisation and selection between two Xiphophorus fish species with different sex chromosome systems. We find that introgression and imposing selection for pigmentation phenotypes results in the retention of an unexpectedly large maternally derived genomic region. During the hybridisation process, the sex-determining region of the X chromosome from one parental species was translocated to an autosome in the hybrids leading to the evolution of a new sex chromosome. Our results highlight the complexity of factors contributing to patterns observed in hybrid genomes, and we experimentally demonstrate that hybridisation can catalyze rapid evolution of a new sex chromosome.
KW  - evolutionary genetics
KW  - experimental evolution
KW  - genome evolution
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228396
VL  - 9
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Kneitz, Susanne
A1  - Volkoff, Helene
A1  - Adolfi, Mateus
A1  - Schmidt, Cornelia
A1  - Fischer, Petra
A1  - Minx, Patrick
A1  - Tomlinson, Chad
A1  - Meyer, Axel
A1  - Warren, Wesley C.
T1  - The piranha genome provides molecular insight associated to its unique feeding behavior
JF  - Genome Biology and Evolution
N2  - The piranha enjoys notoriety due to its infamous predatory behavior but much is still not understood about its evolutionary origins and the underlying molecular mechanisms for its unusual feeding biology. We sequenced and assembled the red-bellied piranha (Pygocentrus nattereri) genome to aid future phenotypic and genetic investigations. The assembled draft genome is similar to other related fishes in repeat composition and gene count. Our evaluation of genes under positive selection suggests candidates for adaptations of piranhas’ feeding behavior in neural functions, behavior, and regulation of energy metabolism. In the fasted brain, we find genes differentially expressed that are involved in lipid metabolism and appetite regulation as well as genes that may control the aggression/boldness behavior of hungry piranhas. Our first analysis of the piranha genome offers new insight and resources for the study of piranha biology and for feeding motivation and starvation in other organisms.
KW  - whole-genome sequencing
KW  - genome annotation
KW  - comparative genomics
KW  - RNA-seq transcriptome
KW  - energy homeostasis
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202218
VL  - 11
IS  - 8
ER  -